package org.apache.maven.model.normalization;

/*
 * Licensed to the Apache Software Foundation (ASF) under one
 * or more contributor license agreements.  See the NOTICE file
 * distributed with this work for additional information
 * regarding copyright ownership.  The ASF licenses this file
 * to you under the Apache License, Version 2.0 (the
 * "License"); you may not use this file except in compliance
 * with the License.  You may obtain a copy of the License at
 *
 *   http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing,
 * software distributed under the License is distributed on an
 * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
 * KIND, either express or implied.  See the License for the
 * specific language governing permissions and limitations
 * under the License.
 */

import java.util.ArrayList;
import java.util.Collections;
import java.util.LinkedHashMap;
import java.util.List;
import java.util.Map;

import org.apache.maven.model.Build;
import org.apache.maven.model.Dependency;
import org.apache.maven.model.Model;
import org.apache.maven.model.Plugin;
import org.apache.maven.model.building.ModelBuildingRequest;
import org.apache.maven.model.building.ModelProblemCollector;
import org.apache.maven.model.merge.MavenModelMerger;
import org.codehaus.plexus.component.annotations.Component;
import org.codehaus.plexus.util.StringUtils;

/**
 * Handles normalization of a model.
 * 
 * @author Benjamin Bentmann
 */
@Component(role = ModelNormalizer.class)
public class DefaultModelNormalizer implements ModelNormalizer {

  private DuplicateMerger merger = new DuplicateMerger();

  public void mergeDuplicates(Model model, ModelBuildingRequest request, ModelProblemCollector problems) {
    Build build = model.getBuild();
    if (build != null) {
      List<Plugin> plugins = build.getPlugins();
      Map<Object, Plugin> normalized = new LinkedHashMap<Object, Plugin>(plugins.size() * 2);

      for (Plugin plugin : plugins) {
        Object key = plugin.getKey();
        Plugin first = normalized.get(key);
        if (first != null) {
          merger.mergePlugin(plugin, first);
        }
        normalized.put(key, plugin);
      }

      if (plugins.size() != normalized.size()) {
        build.setPlugins(new ArrayList<Plugin>(normalized.values()));
      }
    }

    /*
     * NOTE: This is primarily to keep backward-compat with Maven 2.x which did not validate that
     * dependencies are unique within a single POM. Upon multiple declarations, 2.x just kept the
     * last one but retained the order of the first occurrence. So when we're in lenient/compat
     * mode, we have to deal with such broken POMs and mimic the way 2.x works. When we're in strict
     * mode, the removal of duplicates just saves other merging steps from aftereffects and bogus
     * error messages.
     */
    List<Dependency> dependencies = model.getDependencies();
    Map<String, Dependency> normalized = new LinkedHashMap<String, Dependency>(dependencies.size() * 2);

    for (Dependency dependency : dependencies) {
      normalized.put(dependency.getManagementKey(), dependency);
    }

    if (dependencies.size() != normalized.size()) {
      model.setDependencies(new ArrayList<Dependency>(normalized.values()));
    }
  }

  protected static class DuplicateMerger extends MavenModelMerger {

    public void mergePlugin(Plugin target, Plugin source) {
      super.mergePlugin(target, source, false, Collections.emptyMap());
    }

  }

  public void injectDefaultValues(Model model, ModelBuildingRequest request, ModelProblemCollector problems) {
    injectDependencyDefaults(model.getDependencies());

    Build build = model.getBuild();
    if (build != null) {
      for (Plugin plugin : build.getPlugins()) {
        injectDependencyDefaults(plugin.getDependencies());
      }
    }
  }

  private void injectDependencyDefaults(List<Dependency> dependencies) {
    for (Dependency dependency : dependencies) {
      if (StringUtils.isEmpty(dependency.getScope())) {
        // we cannot set this directly in the MDO due to the interactions with dependency management
        dependency.setScope("compile");
      }
    }
  }

}
